1. Field of the Invention
The disclosed embodiments relate to a nanoporous membrane, a process of fabricating the same, and a device for a controlled release of biopharmaceuticals including the same, and more particularly, to a nanoporous membrane through which materials having a several nanometer size, for example, a material having an average diameter of 10 nm or less, pass according to a single-file diffusion, a process of fabricating the same, and a device for a controlled release of biopharmaceuticals including the same.
2. Description of the Related Art
Membrane filtration technologies are widely used throughout almost all industrial fields, for example, to produce ultrapure water in the electronics field, to separate medicines, such as protein, enzyme, antibody, etc., in the biotechnology field, or in a concentration process in the food industry. Membrane filtration technologies can be classified into microfiltration, ultrafiltration, nanofiltration, etc., according the size of a material to be filtered.
In general, membranes used in such filtration technologies can be manufactured using polymers. A method of manufacturing a filtration membrane is disclosed in Korean Patent Laid-open No. 10-2005-0029603. Membrane manufacturing processes can be classified into processes of manufacturing a membrane having a nominal pore size and processes of manufacturing a membrane having an absolute pore size. Processes of manufacturing a membrane having a nominal pore size involve stretching, interfacial polymerization, phase-inversion, etc. Processes of manufacturing a membrane having an absolute pore size involve track-etching in which pores are formed through the irradiation of a radioactive element and corrosion for a predetermined time.
A membrane having a nominal pore size includes pores which are abnormally larger than the nominal pore size, has poor pore size uniformity on the surface thereof, and thus cannot be used to separate or purify a particular material with a high purity. Meanwhile, a membrane having an absolute pore size has high pore size uniformity on the surface thereof and thus can purify a material with a desired high purity. However, the membrane having an absolute pore size has a low surface pore density and a thick first separation layer, which lower the flux of the membrane.
Meanwhile, membranes can also be used as a path of biopharmaceuticals in a device for a release of biopharmaceuticals. For example, an implant type device for a release of biopharmaceuticals has been recently applied in various clinical fields since each medical treatment lasts to several months, thereby economical. In order to efficiently release biopharmaceuticals in the implant type, the release speed of the biopharmaceuticals needs to be constantly controlled regardless of the concentration of the biopharmaceuticals in a container.